The use of fiber or foam cores for such applications is extremely advantageous because it enables the weight of the batteries to be considerably reduced. But, in addition to its light weight, the core of the electrode must be highly porous, it must be conductive, and it must be mechanically strong enough at the bond between it and its electrical connection which is a rigid metal conductor, e.g. a steel strip.
Such bonding is generally performed by welding. The edge of the core is pressed against the connection, and it is welded thereto under pressure. Patent Application FR-A-2 604 302 and U.S. Pat. No. 5,085,956 describe such methods.
In another variant, it is possible to use two metal strips, one on each side of an edge of the core of the electrode, the strips being welded to the core electrically.
It has been observed that such solutions are not satisfactory with respect to the electrical and mechanical performance levels of the electrode.